1. Field of the Invention
The present invention relates to a moving image processing technique and, in particular, to improvement in a scene determination technique in moving images.
2. Description of the Background Art
In a conventional moving processing, there is known a method in which a scene change in a moving image is determined by detecting a change in brightness or the like for every frame constituting the moving image, and a common scene characteristic which is a common moving image characteristic among a frame group having substantially the same scene from that scene change to the next scene change is determined.
Then, on the basis of a correction parameter corresponding to the common scene characteristic, image correction is executed for the frame group by one operation, thereby making the moving processing more efficient and appropriate.
In the above moving image processing, the common scene characteristic is determined on the basis of only the scene determination with respect to a frame directly after a scene change, however, the frame directly after a scene change is not always sufficiently scene changed, so that the determination accuracy of common scene characteristic is often poor.
On the other hand, in a conventional moving image correction, first a change in brightness or the like is detected for every frame image (hereinafter, simply referred to as “frame”) constituting the moving image as a preliminary processing, whereby a scene change in the moving image is detected. Then, a frame group from that scene change to the next scene change is regarded as a frame group representing substantially the same scene, and a common scene characteristic as a scene characteristic which is common among the frame group is determined. To be more specific, a characteristic of a scene represented by a frame directly after a scene change is determined, and the result of determination is defined as a common scene characteristic.
After that, a correction parameter corresponding to the common scene characteristic is determined, and on the basis of the correction parameter, the same image correction is executed on the frame group. In this way, moving image correction is made more efficient and appropriate.
By the way, in determination of a scene characteristic represented by a frame (hereinafter, referred to as “scene determination”), there is a case that it is preferred to determine as indiscriminable because reliability of the determination result is poor. In such a case, it becomes impossible to determine a common scene characteristic and a correction parameter, so that it becomes necessary to take such measures of, for example, executing correction of a frame group that is indiscriminable by using a correction parameter used for correction of a preceding frame group.
Also, scene determination with respect to a frame is almost the same as a scene determination executed in correction of a static image, and measures in the case of indiscriminable should be taken not only for moving images but also for static images.